This invention relates to a surgical probe and more particularly to a surgical probe for the detection of embedded anatomical structures and pulsing blood vessels.
Historically, surgery has been a physically traumatic experience. Surgical techniques often involved large incisions in the body to allow the surgeon both to see and feel organs and tissues that were being removed or repaired. While medicine in general has flourished in the 20th Century with innovations such as penicillin and x-ray machines, surgery has not progressed technologically nearly so quickly as other fields of medicine. Until the early 1980's the most significant surgical advance had been the invention of general anesthesia in 1846.
The early 1980's began what has become a revolution in surgery called minimally invasive surgery (MIS). This revolution in surgery in turn resulted in large measure from the development of imaging techniques employing cameras with charge coupled devices (CCD) as the image capturing element. CCD elements are very small (3.4 mm by 6 mm is standard) and can be used to make tiny cameras because they allow the image to be digitized at the camera lens but processed by electronics which may be separated from the camera itself.
In minimally invasive surgery, the surgeon makes several small (1-2 cm) incisions in the body and uses long, slender tools such as endoscopic forceps and scalpels, inserted through small incisions, to manipulate tissue inside the body. The surgeon watches what he or she is doing on a video monitor. The image on the monitor is generated by an endoscope, a long slender camera/lens system typically 10 mm in diameter, which is inserted through one of the incisions.
Minimally invasive surgery reduces trauma to the patient, greatly reduces patient recovery time and leaves very little scarring. The first procedure routinely performed by minimally invasive surgery was removal of the gall bladder. This procedure is known as cholecystectomy.
Despite the great medical promise of minimally invasive surgery, the technique is still in its infancy due in large measure to the fact that the surgeon has virtually no sense of touch during such procedures. Instead, the surgeon must rely purely on visual feedback from the endoscope to ensure that he or she is performing the tasks properly. For most procedures, tactile feedback is crucial in order to manipulate properly delicate body tissues and to diagnose correctly the state of disease. Further, surgeons must take great care during minimally invasive procedures not to puncture accidentally an embedded blood vessel that is not visible in the endoscope image. Tumors are also difficult to locate visually during minimally invasive surgery.
The lack of tactile feedback is a great disadvantage in the case of cholecystectomy. The gall bladder is removed usually because the bile ducts have been blocked by stones that often develop in elderly patients at the junction between the gall bladder and the cystic duct. Because the cystic duct and cystic artery are often directly next to each other, they may be indistinguishable by visual observation provided by an endoscope. Surgical complications often result and a significant number of laproscopic cholecystectomies are converted to open cholecystectomy in order to give the surgeon a better visual field.
Modem surgical instruments for minimally invasive surgery include high resolution endoscopic camera systems and high quality endoscopes for imaging during the procedure. The tools most frequently used by surgeons are the endoscopic scalpel, forceps, and grasps. Although some tactile array sensors have been adapted to surgical probes, they are not routinely used in surgery. This lack of routine use may be due to their rigid structure that does not lend itself well to tactile sensing of curved geometries such as human organs.
Surgeons have also used invasive Doppler probes in heart studies and in invasive imaging techniques. Such pulsed Doppler systems are electronically complex because they rely on precisely timed circuitry to parse the incoming and outgoing signals. Simpler ultrasonic devices are known for detecting flow. Such devices use the Doppler effect with a continuous wave ultrasonic signal. Such devices have been used to determine information on blood flow in surface arteries.
Currently, there are no devices known to the inventors that can detect motion or flow so as to localize pulsing blood vessels and also provide a representation of the shape of an object within the body.